Right Hand Upper Locking Feedback Actuator Proximity Switch Signal Failure on Channel A

TASK 78-31-00-810-947-A
Right Hand Upper Locking Feedback Actuator Proximity Switch Signal Failure on Channel A

1. Possible Causes

R UPPER ACTUATOR [3042KM1]
HARNESS - RIGHT TRAS [4132KS]
HARNESS - PYLON T/R [4130KS]
EEC WIRING HARNESS WF06 [4089KS]
PROX SENSOR-R T/R UPPER PRIMARY LOCK, CHAN A [4033KS]
[4000KS]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
TSM TASK 71-00-00-810-843-A	Nacelle Component and Harness Troubleshooting Procedure for Guidance Troubleshooting Intermittent Faults
AMM 71-13-00-010-802	Opening of the Fan Cowl Doors
AMM 71-13-00-410-802	Closing of the Fan Cowl Doors
AWM 715135
AWM 715178
AMM 73-21-01-000-801	Removal of the Electronic Engine Control (EEC)
AMM 73-21-01-400-801	Installation of the Electronic Engine Control (EEC)
AMM 73-21-66-000-802	Removal of the Electronic Engine Control (EEC) Wiring Harness (WF06)
AMM 73-21-66-400-802	Installation of the Electronic Engine Control (EEC) Wiring Harness (WF06)
AMM 78-31-00-210-802	General Visual Inspection (GVI) of the Proximity Sensor Targets
AMM 78-31-00-710-805	Operational Test of Thrust Reverser with MCDU
AMM 78-31-04-000-801	Removal of the TRAS Locking-Feedback Actuator
AMM 78-31-04-400-801	Installation of the TRAS Locking-Feedback Actuator
AMM 78-31-20-000-801	Removal of the TRAS Actuator Proximity-Sensors
AMM 78-31-20-400-801	Installation of the TRAS Actuator Proximity-Sensors
AMM 78-31-61-000-812	Removal of the Right TRAS Monitoring Harness
AMM 78-31-61-000-813	Removal of the Pylon TRAS Monitoring Harness
AMM 78-31-61-400-812	Installation of the Right TRAS Monitoring Harness
AMM 78-31-61-400-813	Installation of the Pylon TRAS Monitoring Harness
AMM 78-32-00-860-802	Manual Extension of the Thrust-Reverser Translating Sleeves
AMM 78-32-00-860-803	Manual Retraction of the Thrust-Reverser Translating Sleeves

3. Fault Confirmation
Subtask 78-31-00-710-262-A ** ON A/C NOT FOR ALL

A. Do the operational test of the thrust reverser with the MCDU to confirm this fault AMM 78-31-00-710-805.
(1) If the maintenance message does not come back, troubleshoot as described in the nacelle component and harness troubleshooting procedure for guidance troubleshooting intermittent faults (Ref. TSM TASK 71-00-00-810-843).
(a) Monitor the engine reoccurring maintenance message.
(2) If the maintenance message comes back (hard fault), go to the Para. Fault Isolation.

4. Fault Isolation

WARNING: BE CAREFUL WHEN YOU DO WORK ON THE ENGINE AFTER SHUTDOWN. THE ENGINE CAN STAY HOT FOR A LONG TIME. IF YOU DO NOT OBEY THIS WARNING, INJURY CAN OCCUR.

CAUTION: MAKE SURE YOU REMOVE ELECTRICAL POWER FROM THE EEC BEFORE YOU REMOVE THE ELECTRICAL CONNECTORS. IF YOU DO NOT OBEY THIS INSTRUCTION, DAMAGE TO THE EEC CAN OCCUR.

Subtask 78-31-00-810-291-A ** ON A/C NOT FOR ALL

A. If there is confirmation of the fault:
(1) Get access to the Right Hand Upper Locking Feedback Actuator and EEC:
(a) Open the fan cowl doors AMM 71-13-00-010-802.
(2) On Actuator, at proximity sensor (4033KS), make sure that the target is not missing and do a visual inspection of the target for bend, breakage or damage AMM 78-31-00-210-802.
(a) If you find a bend, breakage or other damage, or if the target is missing:
1 Replace R UPPER ACTUATOR [3042KM1] AMM 78-31-04-000-801 and AMM 78-31-04-400-801.
2 Do the test given in Para. 3.
(3) If you find no damage or if the fault continues:
(a) Check for the correct engagement of connector (4033KS-A) and proximity sensor (4033KS):
1 Repair as necessary.
2 Do the test given in Para. 3.
(4) If the check is OK or if the fault continues, disconnect connector (4033KS-A) and do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(a) If you find damage, replace HARNESS - RIGHT TRAS [4132KS] AMM 78-31-61-000-812 and AMM 78-31-61-400-812.
(b) Reconnect connector (4033KS-A).
(c) Do the test given in Para. 3.
(5) If you find no damage or if the fault continues, disconnect connector (4054VC-A) AWM 715178.
(a) Do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(b) Do a continuity check (less than 5 ohms) between the pins of connectors (4033KS-A) and (4054VC) as follows:

Pin 2 and pin 4
Pin 5 and pin 13
Pin 3 and pin 14.

(c) Do a check of each wire for wire-to-wire, short circuit and short to ground.
(d) If you find a fault:
1 Replace HARNESS - RIGHT TRAS [4132KS] AMM 78-31-61-000-812 and AMM 78-31-61-400-812.
2 Reconnect all connectors.
3 Do the test given in Para. 3.
(6) If you find no damage or if the fault continues, disconnect connector (491VC-A) AWM 715178.
(a) Do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(b) Do a continuity check (less than 5 ohms) between the pins of connectors (4054VC-A) and (491VC) as follows:

Pin 4 and pin 32
Pin 13 and pin 14
Pin 14 and pin 31.

(c) Do a check of each wire for wire-to-wire, short circuit and short to ground.
(d) If you find a fault:
1 Replace HARNESS - PYLON T/R [4130KS] AMM 78-31-61-000-813 and AMM 78-31-61-400-813.
2 Do the test given in Para. 3.
(7) If you find no damage or if the fault continues, disconnect connector P7 from EEC AWM 715135.
(a) Do a visual inspection of the connector for bent pins, contamination or corrosion or other signs of damage.
(b) Do a continuity check (less than 5 ohms) between the pins of connectors P7 and (491VC-A) as follows:

Pin s and pin 32
Pin r and pin 14
Pin q and pin 31.

(c) Do a check of each wire for wire-to-wire, short circuit and short to ground.
(d) If you find a fault:
1 Replace EEC WIRING HARNESS WF06 [4089KS] AMM 73-21-66-000-802 and AMM 73-21-66-400-802.
2 Reconnect all connectors.
3 Do the test given in Para. 3.
(8) If you find no fault or if the fault continues, check proximity sensor:
(a) Disconnect connector (4033KS-A).
(b) Do a visual inspection of the proximity sensor (4033KS) for bent pins, contamination or corrosion or other signs of damage.
(c) Manually extend the right thrust reverser translating sleeve AMM 78-32-00-860-802.

NOTE: Make sure that actuator is unlocked and pinned.

(d) At proximity sensor (4033KS), make sure that the resistance is less than 1.3 kohms between pins 2 and 5.
(e) At proximity sensor (4033KS), make sure that the resistance is more than 100 kohms between pins 2 and 3.
(f) Manually retract the right thrust reverser translating sleeve AMM 78-32-00-860-803.

NOTE: Make sure actuator is locked.

(g) At proximity sensor (4033KS), make sure that the resistance is in the range 6.5 and 7.5 Kohms between pins 2 and 5.
(h) At proximity sensor (4033KS), make sure that the resistance is more than 100 kohms between pins 2 and 3.
(i) If you find a fault, replace PROX SENSOR-R T/R UPPER PRIMARY LOCK, CHAN A [4033KS] AMM 78-31-20-000-801 and AMM 78-31-20-400-801.
(j) Do the test given in Para. 3.
(9) If you find no fault or if the fault continues, replace [4000KS] AMM 73-21-01-000-801 and AMM 73-21-01-400-801.

5. Close-up
Subtask 78-31-00-860-056-A ** ON A/C NOT FOR ALL

A. Put the aircraft back to its initial configuration.
(1) Make sure that the work area is clean and clear of tools and other items.
(a) Close the fan cowl doors AMM 71-13-00-410-802.

[Rev.8 from Aug 2018] 2026.04.04 04:41:32 UTC